Code detecting apparatus



June 14, 1955 c. E. STAPLES 2,710,951

CODE DETECTING APPARATUS Filed Aug. 17 1951 a E i 1.1 T i i NH RI? 7 LLL.--

a M a i a MR br i i .1 3' I 2 II L 0 Hi I Controlled a Circuit LB NINVENTOR. Crawford if Staples BY ULRHW.

HIS ATTORNEY United States Patent CODE DETECTING APPARATUS Qrawford E.taples, Pittsburgh, Pa., assignor to Westinghouse Air Ilrake Company,Wilmerding, Pa., a corporation of Pennsylvania Application August 17,1951, Serial No. 242,311

1 Claim. (Cl. 340-447) My invention relates to code detecting apparatusfor use in connection with coded signaling systems, and moreparticularly relates to an arrangement for providing code detectionapparatus which will detect the recurrent operation of any one or anycombination of a plurality of recurrently operating contacts.

In coded signaling systems, it is sometimes required to detect the codefollowing operation of any one or any combination of a plurality ofrecurrently operating contacts, which may or may not be operating insynchronism.

It has previously been proposd to provide a separate code detectingarrangement including a code detecting relay to check the recurrentoperation of each of the code following contacts, and to govern thecontrol circuits over contacts of the associated code detecting relaysin series or in multiple. Such arrangements require the use of aseparate code detecting relay for each of the code following contacts,the operation of which it is desired to check.

It is an object of my invention to provide code detecting apparatus forchecking the recurrent operation of a plurality of contacts whichapparatus requires the use of only one code detecting relay, which relayis energized when any one or any combination of the code followingcontacts are recurrently operated, whether or not the contacts operatein synchronism.

Another object of my invention is to provide a simplified code detectingapparatus for detecting the operation of a plurality of recurrentlyoperating contacts, which apparatus does not normally require theexpenditure of energy.

A further object of my invention is to provide code detecting apparatusof an improved type, in which a common code detecting relay is suppliedwith energy from energy storage devices the charging of which isgoverned by a plurality of recurrently operating contacts.

Still a further object of my invention is to provide code detectingapparatus in which an individual storage capacitor is associated witheach of a plurality of recurrently operating contacts, and is arrangedto be charged when the associated contact is in one of its twopositions, and to be discharged through the winding of a common codedetecting relay when the contact is in the other of its two positions.

Other objects of my invention and features of novelty thereof will beapparent from the following description taken in connection with theaccompanying drawing.

In practicing my invention, I provide a code detecting relay of the slowrelease type, which is constructed and arranged so that its contactswill remain picked up during intervals in which no energy is supplied toits winding, provided these intervals do not exceed a predeterminedlength. Additionally, I provide a suitable capacitor associated witheach of the recurrently operated contacts the operation of which it isdesired to detect. Each of these capacitors is charged from a source oflow voltage direct current energy when the contact of the asso ciatedrelay is in one of its two positions. When the con- 2,710,951 PatentedJune 14, 1955 tact is operated to its other position, the energy whichis stored in the capacitor is supplied to the winding of the common codedetecting relay, to thereby energize the relay.

I shall describe one form of code detecting apparatus embodying myinvention, and shall then point out the novel features thereof inclaims.

The accompanying drawing is a diagrammatic view of a circuit arrangementfor detecting the operation of one or the other or both of two codefollowing relays, adapted to be recurrently energized by a line circuitwhich is supplied with coded energy of one polarity at times, theopposite polarity at other times, and impulses of alternate polarity atstill other times.

Referring to the drawing, there is shown a pair of code following relaysNR and RR, which may be of the polar bias type, that is, of a type inwhich the contacts are picked up when and only when energy flows throughthe winding of the relay in a direction indicated by the arrow on thesymbol for the relay coil. A suitable pair of capacitors NQ and RQ areassociated with the relays NR and RR, respectively. A code detectingrelay NRPR of the slow release type is provided and is controlled by therecurrent operation of the contacts of relays NR and RR, in a manner tobe subsequently described. The slow releasing characteristic of relayNRPR is symbolically indicated by the downwardly pointing Vertical arrowthrough the contact of the relay.

The condensers NQ and RQ are supplied with energy from a source of lowvoltage direct current, such as the battery LB shown, having itspositive terminal designated by the reference character B and itsnegative terminal designated by the reference character N.

Also associated with the contacts of relays NR and RR are two resistorsR1 and R2, the function of which will be later described. The relays NRand RR are adapted to be energized by coded energy supplied over acircuit including the wires 5 and 7. The apparatus shown at theright-hand end of the sheet is arranged to supply energy in the form ofimpulses having one polarity at times, having the opposite polarity atother times, and having an alternate polarity still at other times. Thisapparatus includes a control switch SW which governs the operation ofthe relays PCR, MCR and PMCR, which determine the polarity of the energysupplied to the Wires 5 and 7 from a control battery CB, and a codingdevice CT, which coding device is constructed and arranged so that itscontacts are recurrently operated at a predetermined rate, for example,times per minute, when the winding of the coding device is connectedacross the terminals of the source of direct current energy, as shown inthe drawing.

It is believed that the description of applicants invention will be bestunderstood by describing the operation of the apparatus under differentconditions of energization of the relays NR and RR.

The apparatus is shown in the drawing in the condition which it assumeswhen the circuit comprising the wires 5 and 7 is deenergized. At thistime the switch SW is in its first or lowermost position, and thecontrol relays PCR, MCR and PMCR are deenergized. Accordingly, no energyis supplied to the circuit including the wires 5 and 7, and the relaysNR and RR are both released. At this time, energy is supplied from thelow voltage source to the condensers NQ and RQ, by circuits includingthe back contacts a of relays NR and RR, having the resistors R1 and R2interposed in series in the circuit, in order to limit the initial surgeof current when the condensers are being charged. It will be seen thatat this time the condensers NQ and RQ are charged to a voltage equal tothat of the direct current source. At this time, no energy is suppliedto the winding of the code detecting relay NRPR, and accordingly, thecontact a of this relay will be released, to thereby interrupt the onecircuit and close the other circuit controlled over this contact.

It will now be assumed that the switch SW is moved to its secondposition, to thereby energize the relay PCR by a circuit which isobvious from the drawing. When relay PCR picks up its contacts, acircuit is established for supplying coded energy to the relays NR andRR which circuit may be traced from the positive terminal of the controlbattery CB, over the recurrently operated contact a of the coding deviceCT, front contact a of relay PCR, wire 5, the windings of relays NR andRR from left to right, wire 7, and front contact b of relay PCR to thenegative terminal of the battery CB. Accordingly, impulses of energywill be supplied to the winding of relays NR and RR at this time. Sincethe flow of energy through the winding of relay NR is in the directionto cause the contacts of the relay to operate, the contact a of relay NRwill be recurrently picked up and released in response to the pulses ofenergy supplied to the relay. Since the flow of energy through thewinding of relay RR is in the opposite direction to that required tooperate the relay, the contact a of relay RR will remain released atthis time. Each time that the contact a of relay NR picks up, itestablishes a circuit for supplying energy from the associated condenserNQ to the winding of the code detecting relay NRPR. Each time thecontact a of relay NR releases, the condenser NQ is recharged throughthe circuit including resistor R1, with the result that the recurrentoperation of contact a of relay NR causes the supply of recurrentimpulses of energy to the Winding of the code detecting relay NRPR.Accordingly, the con tact a of relay NRPR will be picked up at thistime, to

thereby open or close the circuits controlled over the con- 1'- tacts.As previously explained, the relay NRPR is sufficiently slow inreleasing that its contact a will remain picked up during the shortintervals between the supply of impulses of energy to the winding of therelay.

It will be seen therefore, that at this time, with the line circuitenergized with energy of a polarity such as to cause the operation ofrelay NR alone, the code detecting relay NRPR will be picked up inresponse to the operation of relay NR.

It Will now be assumed that the switch SW is moved to its thirdposition, to thereby deenergize relay PCR and energize relay MCR by anobvious circuit. When the contacts of relay MCR pick up, a circuit isestablished for supplying energy of opposite polarity to the circuitincluding the line wires 5 and 7, which circuit may be traced from thepositive terminal of battery CB, over from contact a of the codingdevice CT, front contact b of relay MCR, back contact b of relay PCR,wire 7, the windings of relays RR and NR from right to left, wire 5,back contact a of relay PCR, and front contact a of relay MCR, to thenegative terminal of the control battery CB. Accordingly, it will beseen that the supply of coded impulses to the windings of relays NR andRR at this time are such as to cause the operation of the contact a ofrelay RR, while the contact a of relay NR will remain released. With thecontact a of relay RR in recurrent operation, the condenser RQ isrecurrently charged with energy from the low voltage source through theresistor R2 each time that contact a of relay RR releases. Each timethat contact a of relay RR picks up, the energy stored in the condenserRQ is supplied through the Winding of relay NRPR. Accordingly, it willbe seen that the code detecting relay NRPR is recurrently supplied withimpulses of energy at this time as the result of recurrent operation ofcontact a of relay RR, with the result that contact a of the codedetecting relay will be picked up to open or close the circuit governedthereby. It is apparent therefore that the code detecting relay NRPRwill be energized by the operation of the relay RR While the relay NRremains inoperative.

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It will now be assumed that the switch SW is moved to its fourth oruppermost position, so that relays PCR and MCR are deenergized and relayPMCR is energized by an obvious circuit. At this time, the line circuitis supplied with impulses of energy of alternately opposite polarity asa result of the operation of the polechanging contacts b and c of codingdevice CT. When the contacts of the coding device CT are picked up, thepositive terminal of battery CE is connected to wire 5 over frontcontact b of coding device CT, front contact a of relay PMCR, and backcontactsaof relays PCR and MCR, and the negative terminal of battery CBis connected to Wire 7 over front contact 0 of coding device CT, frontcontact b of relay PMCR, and back contacts b of relays PCR and MCR. Whenthe contacts of the coding device CT are released, the connections tothe battery CB are reversed. Accordingly, the relays NR and RR arerecurrently energized by pulses of energy of alternately oppositepolarity. The alternate polarity of the code impulses will cause therelays NR and RR to alternately pick up and release, so that thecondensers NQ and RQ are alternately connected to the source of energyto receive a charge therefrom. During the time that the contacts a ofthe relays NR and RR are picked up, the energy stored in theirrespectively associated capacitors is discharged through the winding ofthe code detecting relay NRPR, so that relay NRPR is picked up underthese conditions also.

It will be apparent from the foregoing that the code detectingarrangement embodying my invention is capable of detecting the codefollowing operation of a plurality of recurrently operated contacts, andit will be readily understood that the contacts need not operate insynchronism, since the energization of the relay NRPR is dependent onlyupon the charge and discharge of the individual capacitors associatedwith the contacts, and not upon the operating time relationship of thecontacts. It will also be understood by those skilled in the art thatthe contacts need not be those of code following relays, but may be anytype of recurrently operated contacts, the operation of which it isdesired to detect.

Although I have herein shown and described only one form of codedetecting apparatus embodying my invention, it is to be understood thatvarious changes and modifications may be made therein within the scopeof the appended claim without departing from the spirit and scope of myinvention.

Having thus described my invention, what I claim is:

In combination, a first and a second code following relay, each having acontact adapted to be recurrently operated between a first and a secondposition in response to impulses of energy supplied to the relay, codingmeans for supplying impulses of energy to said first and second relaysalternately, whereby the contacts of said relays are recurrently andalternately picked up and released, a first and a second capacitorassociated with said first and said second relays, a source of directcurrent energy, means for charging said capacitors from said sourceincluding the contact of the associated code following relay closed inits first position, a slow release codedetecting relay, means fordischarging the energy stored in each of said capacitors through awinding of said codedetecting relay including the contact of theassociated code following relay closed in its second position, and

a circuit governed by said detecting relay.

References Cited in the file of this patent UNITED STATES PATENTS2,442,427 Mullerheim June 1, 1948 2,462,655 McHenry Feb. 22, 19492,472,526 Frazee June 7, 1949 2,504,996 MacDonald Apr. 25, 1950

